


Forbidden Love

by AutumnalRain



Series: Two Paramedics and a Fireman [1]
Category: Chicago Fire
Genre: Acceptance, Established Relationship, Family, Friendship, Hurt/Comfort, former established relationship - Freeform, post-season 8
Language: English
Status: Completed
Published: 2021-01-10
Updated: 2021-01-11
Packaged: 2021-03-14 09:59:45
Rating: General Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 2,672
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28668861
Author URL: https://archiveofourown.org/users/AutumnalRain/pseuds/AutumnalRain
Summary: Gabby returns to Chicago to visit her former Firehouse, in hopes of reconciling her relationship with Casey. However, instead she finds out that Matt has already moved on with her former best friend and Ambo partner. Will Gabby be able to convince Matt that she is who he has always wanted, or was her Matt Casey, in fact Sylvie Brett's Matt Casey?
Relationships: Matthew Casey/Gabriela Dawson, Sylvie Brett/Matthew Casey
Series: Two Paramedics and a Fireman [1]
Series URL: https://archiveofourown.org/series/2124954
Comments: 23
Kudos: 78





	1. Appearances

Gabby stepped foot onto the grassy surface, appreciating the feeling of the warm sun shining down onto her bare shoulders. She was visiting Chicago after she had been once again sent down from Puerto Rico to attend their charity fundraiser. So much had changed in the past two years, but the one thing that hadn’t was her love for Matt Casey. Whilst she was the one who decided to step away from their marriage, she knew it was a decision she would live to regret. She had tried hard to move on and find a new relationship, but after their night together last year, she realised that Matt was the man she wanted to spend the rest of her life with. Following their night together the previous year, Casey and Dawson maintained regular contact, catching one another up on the happenings of Chicago and Puerto Rico.

Gabby had found out that the week she was back in Chicago was the week that the. CFD picnic was also on. Using his opportunity, she decided to visit 51, seeing them on their day off as opposed to visiting the firehouse where there would always be the risk of them being called out, interrupting Gabby’s catch up.

Scouring her eyes around, she saw Hermann with his family, Mouch and the two younger firefighters, Ritter and Gallo sitting at the table, all smiling and chatting with one another. She started to approach the table whilst continuing to scan the park for the person she most wanted to see. She also missed it but doing a take, she looked to the table to the left of Hermann and his table, she saw Stella and Severide sitting next to one another, laughing with the man and woman whose backs were facing Gabby.

Gabby gasped in shock, recognising the backs of the two blondes laughing with Kidd and Severide. _“It can’t be…”._ As the blonde man leaned down to plant a kiss on the blonde females check, his hands sneaking around her waist in clear affection, Gabby’s heart broke into a million pieces. Her former best friend was with her ex-husband.

* * *

“Wait… so you are telling me. Big man, Severide here got scared of your clown mask after watching IT?” Casey burst out into laughter once again. Never did he think he would see the day where the Squad Lieutenant would cower to his girlfriend, looking for protection. Casey wished he had witnessed this scene.

“Oh don’t laugh, Casey. I’m sure there are things you’re afraid of and would go running to Brett for” Kelly grumbled, though there was a small smile lingering on his lips. Suddenly, he felt Kidd go taught. Wondering what his girlfriend just witnessed, he followed her eye gaze. Casey and Brett also followed suit, turning around.

The sight that greeted them left them in surprised. Casey immediately went tense, his arms tightening around Brett’s waist. Whilst, he and Gabby had kept in contact with one another, the one thing he hadn’t done, or rather, couldn’t bring himself to do was tell his ex-wife that he had been dating her former ambo partner for the last 4 months. He had been meaning to but he kept putting it off, thinking that he wouldn’t be seeing her any time soon. The four members of 51 saw the hesitant smile on her face, Casey and Brett realising she had seen their intimacy play out.

Seeing Gabby slowly walk towards them, they all stood up to greet her.

“Dawson! What are you doing here girl?” Kidd and Gabby hugged each other tightly.

“The annual fundraiser again” Gabby quietly said, them all understanding what it implied. _Casey and Dawson having a do-over of the last fundraiser_ rang in everyone’s head.

Brett smiled nervously. She knew Matt hadn’t told Gabby about their relationship and now she didn’t know what to expect. Immediately she started to doubt their relationship. Was their relationship serious to Matt? Or was she just a rebound and a placeholder until Gabby returned to Chicago? Avoiding Matt’s eyes and barely able to hold eye contact with Gabby, Brett went to hug her former best friend and Ambo partner. “Hey Dawson” Sylvie tried to let out a small smile, hoping it didn’t look more like a grimace.

“Hey, Brett”. Dawson smiled, pulling back from their hug and stood back, making the rounds around the group. Eventually it was Casey’s turn. She lent in to hug, giving him a tight hug, inhaling in his scent. It hadn’t changed one bit, his scent still smelling of the same firey wood, and her body slotted into her arms like nothing had changed. She remembered this feeling, the feeling of safety and comfort, the arms she spent both happy moments and her lowest moments in. clearing her throat, Gabby willed herself to pull back from the hug. “Hey Matt”, dazzling her ex-husband with the same smile that had always enchanted him.

“Gabby, How have you been?”. Matt stepped closer to Brett, attempting to give his girlfriend a reassuring smile whilst stuffing his hands into his jean pockets, unsure of what to do with himself and whether it was appropriate for him to acknowledge his and Brett’s relationship to Gabby.

Gabby kept up a strong front, never letting her smile waver or showing her true emotions. “I’ve been good. I just wanted to drop by and say hi to the firehouse. See how everyone is going”. Eventually she averted her gaze from Casey and turned her attention to the rest of the group. She could tell that everyone was a little on edge. Probably from their knowledge of Matt and Sylvie’s relationship. Out of the corner of her eyes she saw Matt’s hand resting on Brett’s lower waist. She knew there was no point in pulling Casey aside and telling him exactly why he had come back to Chicago.

Before anybody else could make any further comments, Hermann came up behind them.

“Heyyyy! There’s my favourite kick-ass firefighter, bartender and paramedic”. Christopher Hermann couldn’t help but use this opportunity to tease Kidd and Brett and their positions in the firehouse. He gave Dawson a tight squeeze, kissing both her cheeks.

“It’s alright, Hermann, you aren’t our favourite firefighter either” Kidd couldn’t help but tease back in jest.

“Ha, Ha” Herman let out a dry laugh in response, before turning his attention back onto his one-time protegee.

Gabby couldn’t let a real smile grace her face, listening to their banter. She missed the group and the friendly jibes they threw at one another. This was something she had really missed, being away from Chicago. “Just here for a fundraiser. Thought I’d pop in, in case your old age forgot my face, Hermann…”.

Just like that Dawson fell back into an easy rhythm with her former colleagues and friends.

* * *

Hours passed and whilst, she did not have a moment to have a private conversation with Brett or Matt, and the couple showed little PDA, she saw the small glances they threw one another throughout the picnic.

Gabby couldn’t help but feel her heart break. She knew she had no claim to Casey. She was the one who walked away. But she also didn’t ever imagine that the Casey she once told Brett she would find would also be _her_ Matt Casey. What Gabby hadn’t told Matt was her visit to Chicago wasn’t just for the fundraiser but that she was willing to reconcile their relationship. Her contract was coming to the end and Gabby had realised that Matt was her home and that whilst Puerto Rico was incredibly rewarding, she wanted to spend the rest of her life with Matt. What she hadn’t planned on seeing was him in a relationship with someone else. A relationship that she could evidently see was full of love. So instead, she picked up her bag and left the picnic without saying good bye. Her chance to love Matt was gone and she had to accept that.

**Notes for the Chapter:**

> At the moment this is a one-shot, however, I have ideas for another chapter or 2 and an alternative ending to the first chapter. Please let me know what you think of this story and whether I should continue or leave it as it is :)


	2. Closure

**Summary for the Chapter:**

> Casey and Brett discuss their relationship and how Gabby's re-appearance will impact them.

The sun was beginning to set and the picnic was wrapping up. Those with families had already begun to trickle out of the park an hour ago, heading home for their dinners. Left over from Firehouse 51 were Casey, Brett, Severide, Kidd, Ritter and Gallo.

“Anyone heading to Molly’s tonight?” Kelly looked around their small group, clearly interested in continuing their festivities.

“I’m in”. “See you guys there” The two youngest members of the Firehouse were just as keen to join in the older guys for a few drinks.

“Casey? Brett?”

Casey nodded in agreement, grabbing onto Sylvie’s hands, pulling her up to stand. “Yeah, we’ll meet you there”. His eyes however, never left Sylvie’s face. He could tell something wqas bothering her and he had an idea of what – or better, _who_ was making her more quiet than usual.

* * *

Sylvie and Matt began their slow walk to Matt’s truck as the small group parted ways. Their arms wrapped around one another. Reaching the car, they both got into their seats, silence settled between the two as they both tried to think of a way to approach the Gabby subject. They both knew they had to discuss the elephant in the room.

“So… it was nice seeing Gabby again” Sylvie noted quietly as she averted Casey’s eyes and played with the bracelet, she had been gifted by Matt on her birthday a few months prior.

Casey could tell that she was beginning to shrink back into her shell. He let out an audible sigh before turning to face Sylvie. He grabbed both her hands, giving them a tight squeeze.

“I know you have your doubts Sylvie, and I know you know that I will always love Gabby. Not in the way I used to love her, and definitely not the way I love you, Sylvie”.

“She was a big part of my life and we went through a lot together. I just want you to remember and know that no matter how many times she comes back, she will always be in my past. She may always have a special place in my heart, but you are my future Sylvie, and I don’t want you to ever forget or doubt that fact.” Gently rubbing circles on the back of her hand, he could feel the tension slowly easing off his girlfriend. “I love you, and only you, Sylvie”.

Sylvie gazed into Matt’s eyes. She knew Matt loved her, but she also knew how much Gabby meant to Matt and the history that lay between the former married couple. Returning Matt’s hand squeeze, she let a smile grace her lips. “I love you too… I just... I just… it’s not that I doubt your love for me Matt… I just will always remember everything Gabby had confided in me with you two’s relationship. I had a front row seat to your relationship and how much you guys loved each other. This is something that I can never erase from my memory”. Matt and Sylvie had, had this conversation back when they first started dating. The only difference is back then, Sylvie very much doubted Matt’s love for her, whereas now she knew Matt would never knowingly hurt her.

Matt gave Sylvie’s hand another gentle squeeze, his hand continuing to encompass her both her hands. “I know that. And for that reason, you will know why Gabby and I didn’t work out and all the problems that arose between us throughout the years”. Matt gave Brett a reassuring smile, before leaning in to give her a soft kiss, ending all conversation and any further worry from Brett.

* * *

In the end, nearly the whole Firehouse rocked up at Molly’s. Severide and Casey were sat at the bar watching the Blackhawks play on the tv screen with beers in their hands, whilst also conversating with Mouch and Hermann as Hermann served drinks to the customers. Across the bar sat Sylvie, Stella, Ritter and Gallo at a table, all four of them chatting away about god-knows-what young people now chat about.

Turning away from Mouch and Hermann, Kelly gained Casey’s attention. “Did you and Gabby get a chance to talk this afternoon?” Kelly knew neither Sylvie, nor Matt had informed Gabby of their relationship and the Squad Lieutenant was worried that drama would erupt if Gabby was unpleased with news of the couple of six months.

“Nah, didn’t get the chance.” Casey took a swig of his beer before continuing on. “I didn’t really have a chance to talk with Dawson in all honesty. There was a lot going on at the picnic and everyone seemed to want to catch up with her considering how long it’s been since each of us have really spoken to her”. Matt, however, was not particularly phased by not getting a moment alone with his ex-wife. He had moved on and he hoped she had as well. Whilst her leaving had left him in a world of hurt, two and a half years later, he had learnt to move on, and move on he did with the blue-eyed PIC.

“Do you think Dawson’s upset about you and Brett?” Severide was curious about the status of their current relationship. He knew how much Dawson had meant to the Captain, but Sylvie was also his honorary little sister, who he aimed to protect despite Casey being his best mate.

“Eh, I really don’t care honestly. Whilst I would like for Dawson to be okay with it all, at the end of the day, I don’t need her approval and neither does Sylvie. She was the one who left”

Kelly raised his brows in surprise at Casey’s candid reply. “… even with what happened at last year’s fundraiser?” continuing to sip on his beer, Kelly pressed on, knowing how happy Matt was following that night. Whilst he didn’t know the exact details, he had an idea of what happened at the fundraiser. “Gabby did say she was here for another fundraiser today. She didn’t ask you to go again?”

“That was closure for me. It was a nice night, but I also realised that night that I needed to move on with my life. Whether she had planned to ask me to go again, I don’t know and I don’t really care because I wouldn’t go”. Casey confirmed with no sign of regret in his tone.

Lifting his beer to Casey’s, they clinked their bottles together. “Cheers to that”. Severide was glad his best friend had finally moved on and opened his eyes to the future he could have with Brett. Kelly was there for him when Gabby had left, and he saw what a mess Casey had become following her departure and eventual divorce. Confirmation that Casey was ready to leave his past in the past reassured him that his friend would be okay. Both men turned their focus back onto the Blackhawks game, letting the night continue on as if they hadn’t just had a heart-to-heart with one another.

Thirty minutes later, Casey heard the beep of his phone, alerting him to a new text message. Opening the message, he let out a small smile. His chest filled with warmth. Gabby was once his miracle, the love of his life who managed to pull him away from the darkness of losing Hallie and Darden, and he would never forget that. But now this very trust was laid on Sylvie, something that Gabby never was able to do ensure. Reading the message one more time, he looked across Molly’s to where Sylvie was laughing out loud at something Gallo said. Matt smiled widely at the beautiful sound of Sylvie’s laugh before looking down at his phone and locking it, ultimately closing the message and slipping the phone back into his pocket.

[Message]

From: Gabriella Dawson -

_Treat her well, Matt. She deserves the best._

Matt knew Sylvie deserved the best and he vowed to himself that he would be the very best person and man he could be to the blonde that owned his heart.

**Notes for the Chapter:**

> This is how I had wanted this story to play out from the very beginning and a few of you guys had actually mentioned this scenario as well, so hopefully it did not disappoint!
> 
> I also have a few ideas about Gabby not accepting Brettsey and letting that play out. Maybe I’ll post this alternate ending to chapter 1, one day.
> 
> Thanks for reading this story :)


End file.
